1. Field of the Invention
The present invention relates to apparatus and methods for displaying graphic information, and more particularly, the present invention relates to a computer controlled display system for displaying and manipulating overlapping windows of data on a display.
2. Art Background
Over the past decade, a variety of graphic user interfaces have been developed to ease human interaction with computer systems. Many user interfaces utilize metaphors in the design of the interface as a way of maximizing human familiarity, and conveying information between the user and computer. Through the use of familiar metaphors, such as desk tops, notebooks and the like, the interface takes advantage of existing human mental structures to permit a user to draw upon the metaphor analogy to understand the requirements of the particular computer system. It is well known that designing around a familiar metaphor helps reduce human learning time. See for example, Patrick Chan "Learning Considerations in User Interface Design: The Room Model", Report CS-84-16, University of Waterloo Computer Science Department, Ontario, Canada, July 1984, and references cited therein.
In current generation systems, it is common for computer systems to incorporate so-called "object oriented" display systems which utilize multiple "windows" on a display in which combinations of text and graphics are disposed. Using a desk top metaphor, the windows may take the form of a variety of objects, such as file folders, loose leaf binders, or simple rectangles, and the windows may overlap one another with the "top" window constituting the current work file. A user operating within the context of a window-based graphic user interface ("GUI") operates on objects commonly found in an office, and therefore, provides non expert users with a familiar surrounding in which to interact with the computer.
In a typical window-based GUI system, visually distinct display objects are provided on the display screen, and are commonly referred to as "icons". Each of the icons represents a function or object on the desktop. In many systems, a cursor is also displayed which may be selectively moved in response to the movement of a mouse or other pointer control device. The cursor may be moved over display objects which the user may select on the screen. The user may delete information from a window, move data from one window to another, and generally operate on the windows as if an actual file or other physical object is being manipulated. A variety of "pull-down" menus also may be displayed, using a technique for selecting particular command options appearing along a menu bar, and subcommand items corresponding to the command options (See U.S. Pat. No. Re. 32,632).
The reader is referred to the following references which describe various aspects, method and apparatus associated with prior art graphic user interface design: U.S. Pat. No. Re. 32,632, U.S. Pat. No. 4,931,783, U.S. Pat. No. 5,072,412, and U.S. Pat. No. 5,148,154, and the references cited therein.
One of the problems associated with window based graphic user interfaces is the necessity of carefully managing display screen space. With multiple windows open, users may find that there is not enough screen space (screen "real estate") to adequately view the various window applications and icons while working. For example, in an audio/video/data (hereinafter "electronic") conferencing system, it is desirable for a user to view an application which is the subject of discussion with a remote user while viewing the remote user in a video window. Frequently, the user will also desire to view a local video window which displays the video image seen by the remote user as well as a video conference control panel. The ability to group windows and selectively ungroup the windows is desired to maximize the allocation of screen space.
As will be disclosed, the present invention provides a process for dynamically switching between a single top level window and multiple top level windows. In addition, the present invention discloses a user interface for dynamically converting between a single top level window and multiple level windows in a window-based display system.